1. Field of the Invention
The present invention relates generally to apparatus for changing tool holders in the vertical spindle of a machine tool, and more particularly to improved apparatus for quickly and automatically changing tool holders in such spindle.
2. Description of the Prior Art
The improved tool changer is adapted for use with a machine tool having a spindle rotatable about a vertical axis. The spindle of such machine tool is adapted to selectively engage and hold any of a plurality of tool holders. One example of such machine tool, spindle and tool holder, is shown and described in U.S. Pat. No. 3,722,363. Another spindle construction is shown and described in U.S. Pat. No. 3,678,801. It should be clearly understood that such machine tool, spindle, and tool holder, per se, form no part of present invention except insofar as the improved tool changer may be used therewith.
Others have developed tool changers for use with such a machine tool, and examples of such known forms of tool changers having a carousel-type tool storage magazine rotatable about a vertical axis, may be shown in one or more of the following U.S. Pat. Nos. 3,722,363; 3,074,147; 2,901,927; 3,452,427; 3,526,033; 3,200,492; 3,662,442; and 3,932,924.
However, many of these prior art devices provide structure which is either unduly complex for some machining operations, or which involve the presence of an intermediate transfer arm between the tool storage magazine and spindle.